The Dorset Senior League outfit will go into the second round tie at Redlands overwhelming favourites but with their dangerous opponents lying third in Division One, nothing can be taken for granted.
Reynolds told Echosport: “Any side that hasn’t lost yet in the league below are a dangerous proposition and with it being a cup game as well we cannot afford to take them lightly.
“In many ways we are on a hiding to nothing and they have everything to gain. We are a scalp for them at the end of the day and we will need to be at our best.”
Upwey have suffered a stuttering start to their league campaign but they did respond last weekend with a 5-1 win over Sturminster Marshall.
Reynolds added: “I would like a cup run anyway, regardless of our league position, and not only that but it is a chance to get another win under our belt to get some momentum going.
“Winning breeds confidence and that is what we desperately need at the moment.”
Darren Samways is a doubt for Upwey but Sam Nichols and Ben Porteous should both be fit to feature.
Weymouth Sports also face a tricky clash at home to Poundbury Rovers (1.30pm).
The Dorchester outfit lie fourth in Division One and Chris Hicks is urging his Senior League troops to be on their guard.
The joint-boss said: “Poundbury are a bit of an unknown quantity to us but we know they will be looking to come here to cause an upset so we will have to be ready.
“Hopefully, we can just carry on from where we left off in last week’s draw at Sturminster Newton and go through.
“We should have a similar squad available so hopefully we will get a similar performance.”
Chucky Taylor is expected to miss the clash for Sports due to his commitments with Weymouth Reserves.
Finally, Portland United Reserves will travel to Swanage Town & Herston Reserves (1.30pm).
The Blues have not seen action since their 3-1 defeat at Sturminster Newton on October 27. They were supposed to host Kingston Lacy last weekend but the game was postponed.